Answer:
Letter C
Explanation:
Salmon have a physiological adaptation that allows osmoregulation to occur in two different environments (seawater and freshwater). There are specific molecules in the salmon gills that "pump" and "remove" Na and Cl ions. When at sea these molecules pump the ions out of the salmon's body and into freshwater, the same molecules remove Na and Cl from the water bringing it into the animal's blood.
Answer:
Genetic variation in a group of organisms enables some organisms to survive better than others in the environment in which they live. Organisms of even a small population can differ strikingly in terms of how well suited they are for life in a certain environment.
Explanation:
Genetic variations are important because a diverse gene pool is good for long-term survival of a species since the environment is always changing, so the diversity of DNA offers the most fit of the species a better chance of surviving because they are most adapted to the constantly changing environment.